If you are setting up a new season and your division structure and teams have remained the same you can copy divisions, teams and rosters from an existing season
Clone a Season
Click the Season Dropdown in the top left and click Settings
Click Create in the top right
Fill in Season information and under Copy From Season select the season you would like to copy. This will copy the season's locations and division structure
If you want to copy teams, under Copy Teams select Yes or No (note: this will create teams, but rosters will not be copied).
If you would like to copy Rosters, set Copy Team Rosters to yes. (note: you can only copy rosters if you are copying teams)
Press Create Season